This invention relates to disposable absorbent articles, such as diapers and adult incontinence products, and more particularly to disposable absorbent articles which have the ability to effectively handle both urine and low-viscosity fecal material.
Many types of disposable absorbent products, such as diapers, are available that have a high capacity for absorbing urine. Disposable products of this type generally comprise some sort of fluid-permeable topsheet material, an absorbent core, and a fluid-impermeable backsheet material. Although these types of absorbent structures may be highly efficient for the absorption of fluids, they cannot absorb bowel movements ( i.e., hereinafter referred to as xe2x80x9cBMxe2x80x9d). Typically, the BM is trapped between the outer surface of the fluid-permeable topsheet and the skin of the wearer, much of it adhering to the wearer""s skin.
To prevent BM from adhering to the wearer""s skin, the caregiver often applies protective or xe2x80x9crepellentxe2x80x9d products such as vaseline or mineral oil to the buttocks and anal region before placing the absorbent article on the wearer. This procedure usually involves the caregiver""s pouring of the oil or lotion, for example, in one of their hands, rubbing both hands together to distribute the substance thereon and then wiping the same on the skin of the infant. To eliminate the need for this wasteful, messy, and easily forgotten procedure, there have been numerous previous attempts to prepare absorbent articles which contain a protective or therapeutic skin care substance on the topsheet.
One substance that has been applied as a lotion to absorbent products to impart a soothing, protective coating is mineral oil. Mineral oil (also known as liquid petrolatum) is a mixture of various liquid hydrocarbons obtained by distilling the high-boiling (i.e., 330xc2x0-390xc2x0 C.) fractions in petroleum. Mineral oil is liquid at ambient temperatures, e.g. 20 xc2x0-25xc2x0 C. As a result, mineral oil is relatively fluid and mobile, even when applied to article topsheets.
Because mineral oil is fluid and mobile at ambient temperatures, it tends not to remain localized on the surface of the topsheet, but instead migrates through the topsheet into the interior of the diaper. Accordingly, relatively high levels of mineral oil need to be applied to the topsheet to provide the desired therapeutic or protective coating lotion benefits. This leads not only to increased costs for these lotioned products, but other detrimental effects as well.
One of these detrimental effects is a decrease in the fluid handling properties as high levels of mineral oil tend to block the topsheet openings. Also, as mineral oil migrates to the interior of the article, it tends to act as a hydrophobic additive, thus decreasing the absorbency of the underlying absorbent core, if one is used. This decrease in absorbency becomes more pronounced as the level of mineral oil applied is increased.
Even without increasing its level, the tendency of mineral oil to migrate once applied has other detrimental effects. For example, the applied mineral oil can transfer to, into and through the packaging or wrapper material for the lotioned product. This can create the need for barrier-type packaging or wrapper films to avoid smearing or other leakage of mineral oil from the product.
To overcome the problems associated with mineral oils, lotions have been applied to absorbent products. Lotioned absorbent products: (1) have therapeutic or protective benefits, (2) do not require relatively high levels of coatings that are liquid at room temperature (e.g., mineral oil); and (3) do not require special wrapping or barrier materials for packaging.
While lotioned absorbent products do solve the problems associated with mineral oils, care has to be taken in application of the lotion to the absorbent products to prevent occlusion of the topsheet. Such occlusion of the pervious topsheet prevents urine from penetrating through the topsheet inevitably leading to leakage. In order to overcome this problem, lotion has been applied to topsheets in such a manner so as to not coat the entire surface of the topsheet thereby leaving portions of the topsheet free of lotion. An example of such a coating technique is the application of lotion in stripes spaced apart from one another. While stripes of lotion do permit urine to penetrate the topsheet there is an added complexity in the application process, there is the potential for non-uniform transfer of the lotion to the skin and the potential for contamination of the untreated areas of the topsheet thereby reducing the transfer of urine to the underlying absorbent element.
Therefore, it is an object of the present invention to provide a disposable absorbent article having a structured carrier having superior urine and BM handling properties. As used herein, the term xe2x80x9cstructured carrierxe2x80x9d refers to any two-dimensional or three-dimensional morphological arrangement designed to carry and then transfer a composition while maintaining pathways such that urine may pass therethrough.
It is a further object of the present invention to provide a structured carrier for a disposable absorbent article having an effective open area and a plurality of apertures having a sufficient effective size to allow urine and low-viscosity fecal material penetration therethrough such that a skin care composition can be applied with relative ease as the concern for occlusion of the structured carrier has been removed. As used herein, the term xe2x80x9cskin care compositionxe2x80x9d refers to any composition which comprises one or more agents which, when transferred from an article to a wearer""s skin, provide a therapeutic and/or protective skin benefit. Representative materials are discussed in detail below.
It is a further object of the present invention to provide an absorbent article having a skin care composition on the outer surface of the structured carrier that is transferable to the wearer""s skin and is effective at producing desired skin benefits and/or reducing the adherence of BM to the skin, thereby improving the ease of BM cleanup while not inhibiting the structured carriers ability to handle urine.
These and other objects are obtained using the present invention, as will become readily apparent from a reading of the following disclosure.
The invention is a disposable absorbent article, such as a diaper. The disposable absorbent article comprises a structured carrier, a liquid impervious backsheet at least partially peripherally joined to the structured carrier, and an absorbent core intermediate the structured carrier and the backsheet. The structured carrier has an inner surface oriented toward the interior of the disposable absorbent article and an outer surface oriented toward the skin of the wearer when the disposable absorbent article is worn. The structured carrier has an effective open area of at least about 12 percent and a plurality of apertures with an effective size greater than 0.1 square millimeters. The outer surface of the structured carrier comprises an effective amount of a skin care composition which is semi-solid or solid at 20xc2x0 C. and which is partially transferable to the wearer""s skin.